Radiation Keratotomy as a Cause

Radial Keratotomy as a Cause of Corneal Transplantation: Risks and Long-Term Complications

Radial keratotomy (RK), a surgical technique popular in the 1970s and 1990s for correcting myopia, has become obsolete due to its late complications, which in many cases have led patients to require a corneal transplant. Below, we explain why this surgery is now a cause of corneal failure and what modern alternatives exist.

What was Radial Keratotomy (RK)?

Technique: Deep radial cuts were made in the cornea with a diamond blade to flatten it and reduce myopia.

Effectiveness: It corrected mild to moderate myopia (up to -6.00 D), but with unpredictable long-term effects.

Complications Leading to Corneal Transplantation

1. Progressive Corneal Ectasia

Radial incisions weaken the corneal structure, causing progressive thinning and a deformation similar to keratoconus.

Result: Severe irregular astigmatism, impossible to correct with contact lenses or glasses.

2. Induced Hyperopia

Over the years, the cornea tends to flatten more than expected, causing a shift from myopia to severe hyperopia (+3.00 D to +6.00 D).

3. Scarring and Corneal Opacities

Poorly healed incisions generate leukomas (opacity) that affect vision.

4. Refractive Instability

The prescription can fluctuate dramatically during the day due to changes in corneal hydration.

5. Ocular Trauma or Spontaneous Rupture

The weakened cornea is fragile: a minor blow (or even rubbing the eyes) can cause a tear along the old incisions.

When is Corneal Transplantation Required After Radiation Keratotomy (RK)?

Transplantation (keratoplasty) is considered in cases of:

✔ Central corneal opacity that impedes useful vision.

✔ Severe ectasia with contact lens intolerance.

✔ Decompensated corneal edema (endothelial failure).

✔ Corneal perforation due to trauma or infection.

Surgical techniques used:

Penetrating Keratoplasty (PKP): Complete replacement of the cornea (common in RK due to involvement of all layers).

DALK (Deep Anterior Lamellar Keratoplasty): If the endothelium is healthy (less common, as RK usually results in full-thickness damage).

RK Transplant Statistics

10-15% of patients who underwent RK in the 1980s and 1990s required a transplant decades later (Journal of Cataract & Refractive Surgery).

Ten-year graft survival is 70% in these cases (vs. 90% in keratoconus).

Recommendations for Patients Undergoing RK

✔ Annual checkups with corneal topography to detect early ectasia.

✔ Avoid contact sports (risk of corneal tear).

✔ Wear rigid contact lenses (RGP or scleral) if irregularities are present.

✔ Consider crosslinking (CXL) if ectasia progresses.